I have been redesigning the firing pin striker mechanism. It's been keeping me busy. I had to scrap the idea of the tension spring trolley. There was no way to attach the tension springs forward of the bolt because of interference with the bolt.
My new idea, after much thought, is to make a spring loaded firing assembly like a bolt action rifle. This assembly will mount on the back of the carrier by the threaded hole already present and one hole on the left side of the carrier which I will drill and tap. The rear trunnion gets replaced with a modified version to allow clearance. The assembly will contain a plunger that gets pushed down as the carrier moves to the rear most position which by a teeter-totter linkage forces the firing pin to move back and compresses a spring and trips a leaf spring to catch the firing pin in its "drawn position". Like a plunger on a pinball machine being pulled back and held. The assembly then freely rides the carrier as it returns to battery. The modified trigger mechanism then releases the leaf spring which is holding the spring loaded firing pin back, by some undetermined but simple linkage, which will then strike the primer and thus starting the whole system over again. I still need to work out a block to prevent out of battery discharge and I have a pretty good idea how to do that.
This assembly will all mount on the back of the carrier and will be able to install with simple hand tools. I will also show how to build the new rear trunnion, which replaces a very simple stamped sheet metal factory one.
Ok my thought is a cocking mechanism something like a Crickett youth rifle PartsList
that get cocked by the carrier impacting the back of the receiver with a lever mechanism.